fastlane is an open-source platform that simplifies Android and iOS deployment by automating every aspect of the development and release workflow, saving hours and integrating with over 400 tools and services. It supports various platforms including iOS, Mac, Android, and cross-platform apps like Flutter, and offers easy setup, running on local machines, and integration with major CI systems. To get started, developers need to install Ruby on their machine, initialize fastlane into their app, and then add lanes for different tasks such as unit testing, UI testing, code style checking, and deployment. Fastlane plugins like XCOV, trainer, test_center, and more can enhance the development process with features like code coverage reporting, JUnit reports, iOS test control, S3 cache tools, icon generation, and automation of changes to project files. The platform also integrates with Bitrise for automated builds and testing, making it a valuable tool for mobile app developers.